Stimulation of particle-induced chemiluminescence in human polymorphonuclear leukocytes by staphylococcal alpha toxin

Staphylococcal alpha toxin is known to be involved in the pathogenicity of Staphylococcus aureus, although the mode of action is not clearly understood. In the present investigation the interaction of alpha toxin with human polymorphonuclear leukocytes (PMNLs) has been followed in vitro by measuring the ability of these cells to trigger a chemiluminescence response in the presence and absence of active phagocytosis. The alpha toxin does not stimulate chemiluminescence when added to nonphagocytizing PMNLs. At low concentrations alpha toxin stimulates chemiluminescence of PMNLs actively phagocytizing opsonized staphylococci. The increased chemiluminescence has two phases, one being immediate and short lived and the other delayed and longer lasting. These responses are dose-related and suggest an action of alpha toxin on the plasma membrane of PMNLs.